1989 pickup crank issue after compression test
08-10-2016, 02:40 PM
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1989 pickup crank issue after compression test
I believe that my 1989 pickup sr5 has low compression in cylinder number 6, so today I decided I would get a compression tester and see if it was low. After disconnecting all the spark plug wires at the distributor, and unplugging the main wire to the distributor. I also unplugged the two wire harnesses next to the ignition coil. (One was larger and grey, the other smaller with only to wire and black). I went to crank the engine and it wouldn't turn over. It made a slight buzzing noise as it always does, (Assuming that's the fuel pump) but it wont crank over. I am planning on getting a new engine soon but until then I need it running.
08-10-2016, 05:02 PM
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The igniter/coil/distributor/plugs have nothing to do with whether the engine will turn over; that's all the starter. I believe the '89 still had no starter relay, so the starter solenoid current goes straight through the ignition switch. That's a lot of current for that switch, which can damage the switch over time, which is probably the reason Toyota put in a starter relay in later years.
But whether you have a relay or not the diagnosis is simple: pull the solenoid wire (the thin one) from the starter. It's usually a 1/4" (ur, 6mm) spade connector. Use your multimeter to see if you get voltage on that lead with key to start. If you do, you could have a high-resistance connection, so take one more step and use a jumper wire straight from the battery to the tab on the motor (this is only about 2amps, so just about any piece of wire will do).
But whether you have a relay or not the diagnosis is simple: pull the solenoid wire (the thin one) from the starter. It's usually a 1/4" (ur, 6mm) spade connector. Use your multimeter to see if you get voltage on that lead with key to start. If you do, you could have a high-resistance connection, so take one more step and use a jumper wire straight from the battery to the tab on the motor (this is only about 2amps, so just about any piece of wire will do).
08-11-2016, 12:54 AM
#3
A problem well-stated is a problem almost solved. It would help if you describe your truck more completely.
Need to know if manual or auto because: The starter relay was added on mid-86 22RE with manual transmissions.
A problem well-stated is a problem almost solved. Exactly what makes the buzzing sound? The fuel pump? The starter relay? the starter solenoid? The starter?
A buzzing sound from relay repeatedly trying to close but failing usually means weak battery or poor connection to the battery. How sure are you that you have a good and fully-charged battery and that connections are clean and tight? Good connection means bare,shiny metal agains bare, shiny metal.
Assuming that you have verified your battery condition and connections...
Like Scope103 says ^^^, use a "jumper" wire to energize the starter solenoid directly. (Setup Illustrated below will reach driver so MAY be used to get it started until you figure out things)
A. If this consistently makes solenoid clunk energetically AND cranks the starter, then your problem could be:
B. If this makes solenoid clunk energetically but starter does not crank, it is most likely your starter solenoid contacts.
Need to know if manual or auto because: The starter relay was added on mid-86 22RE with manual transmissions.
A buzzing sound from relay repeatedly trying to close but failing usually means weak battery or poor connection to the battery. How sure are you that you have a good and fully-charged battery and that connections are clean and tight? Good connection means bare,shiny metal agains bare, shiny metal.
... I believe the '89 still had no starter relay, so the starter solenoid current goes straight through the ignition switch. That's a lot of current for that switch, which can damage the switch over time, which is probably the reason Toyota put in a starter relay in later years.
But whether you have a relay or not the diagnosis is simple: pull the solenoid wire (the thin one) from the starter. It's usually a 1/4" (ur, 6mm) spade connector. Use your multimeter to see if you get voltage on that lead with key to start. If you do, you could have a high-resistance connection, so take one more step and use a jumper wire straight from the battery to the tab on the motor (this is only about 2amps, so just about any piece of wire will do).
But whether you have a relay or not the diagnosis is simple: pull the solenoid wire (the thin one) from the starter. It's usually a 1/4" (ur, 6mm) spade connector. Use your multimeter to see if you get voltage on that lead with key to start. If you do, you could have a high-resistance connection, so take one more step and use a jumper wire straight from the battery to the tab on the motor (this is only about 2amps, so just about any piece of wire will do).
Like Scope103 says ^^^, use a "jumper" wire to energize the starter solenoid directly. (Setup Illustrated below will reach driver so MAY be used to get it started until you figure out things)
A. If this consistently makes solenoid clunk energetically AND cranks the starter, then your problem could be:
- Your starter relay wiring OR
- The absence of a starter relay.
B. If this makes solenoid clunk energetically but starter does not crank, it is most likely your starter solenoid contacts.
Last edited by RAD4Runner; 08-11-2016 at 01:01 AM.
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